Systems and methods are described for processing an emission signal, such as a fluorescent signal, to compensate for noise in an excitation beam, such as a laser beam. As one example, a scanning system is described that includes an excitation signal generator that provides an excitation signal having one or more representative excitation values representative of an excitation beam; an excitation reference provider that provides at least one excitation reference value; a normalization factor generator that compares the excitation reference value to at least one representative excitation value, thereby generating a normalization factor; and a comparison processor that adjusts at least one emission value corresponding to the at least one representative excitation value based, at least in part, on the normalization factor.